Trends in ww/dw concentration vs. trends in Fulton’s condition index

Fulton’s index (or Fulton’s condition factor ) is given by K = 100(W/L³)
See Wikipedia

Number of time series

##                  Parameter
## country           CD PB HG CB118 CB153 PA PYR
##   Denmark         71 71 71    71    71 71  71
##   Spain           42 42 42    42    42 42  42
##   The Netherlands  3  3  3     3     3  3   3

Example

CD at station BOCHTVWTM

Analyse trends

W.w. conc. trend vs. Fulton trend

• the x axis is the slope of the time trend of Fulton’s index
  
• the y axis is the slope of the time trend of w.w. concentration
  

Ww trend minus dw trend, vs. Fulton trend

• the x axis is the slope of the time trend of Fulton’s index
  
• the y axis is the difference in time trends (w.w. minus d.w.)
  

Ratio of Ww trend / dw trend, vs. Fulton trend

• the x axis is the slope of the time trend of Fulton’s index
  
• the y axis is the ratio of time trends (w.w. divided by d.w.)
  

More examples

In all plots,
* DRYWT = dry weight percentage
* Fultons = Fulton’s index
* Param Conc = Wet weight concentration

Negative trend in both w.w. concentration and Fulton’s index

CD at station MGACED

Negative trend in Fulton’s index, no trend in w.w. concentration

PB at station BOCHTVWTM

Negative trend in Fulton’s index, positive trend in w.w. concentration

CD at station NJY MSS11

Positive trend in Fulton’s index, negative trend in w.w. concentration

PB at station MGAPIN